US4396967A - Multielement magnetic head assembly - Google Patents
Multielement magnetic head assembly Download PDFInfo
- Publication number
- US4396967A US4396967A US06/253,959 US25395981A US4396967A US 4396967 A US4396967 A US 4396967A US 25395981 A US25395981 A US 25395981A US 4396967 A US4396967 A US 4396967A
- Authority
- US
- United States
- Prior art keywords
- ferrite
- magnetic head
- substrate
- head assembly
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/17—Construction or disposition of windings
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/29—Structure or manufacture of unitary devices formed of plural heads for more than one track
- G11B5/295—Manufacture
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/49036—Fabricating head structure or component thereof including measuring or testing
- Y10T29/49043—Depositing magnetic layer or coating
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/49048—Machining magnetic material [e.g., grinding, etching, polishing]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/49055—Fabricating head structure or component thereof with bond/laminating preformed parts, at least two magnetic
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
- Y10T29/4906—Providing winding
- Y10T29/49064—Providing winding by coating
Definitions
- This invention relates to a multielement magnetic head, and in particular to a simplified assembly of a ferrite magnetic head useful for recording data on multiple tracks of a magnetic medium.
- An object of this invention is to provide a multielement magnetic head assembly that simplifies the machining process and realizes a high yield in production.
- Another object of this invention is to provide a multielement magnetic head assembly that allows close separation between recorded tracks with reduction in the tolerances for track position and track width.
- Another object is to provide a multielement magnetic head assembly that employs a relatively small quantity of ferrite with a significant reduction in costs.
- Another object is to provide a multielement magnetic head assembly that is more precise in track position than was previously possible.
- some types of multitrack or multielement magnetic heads used for magnetic tape recorders are constructed from ferrite sections separated by glass.
- the ferrite is initially machined and lapped into rectangular blocks, and saw cut to allow the insertion of glass between the sections that will define track width. It is generally necessary to use a relatively thick ferrite layer to minimize cracking of the brittle ferrite material during cutting and processing.
- the amount of ferrite material used is for mechanical strength, and is not required for electrical or magnetic considerations.
- FIGS. 1A through 1D are isometric views illustrating the process steps for fabricating a closure piece for a magnetic write head, in accordance with this invention
- FIG. 1E is an isometric view of a completed magnetic head closure piece
- FIG. 2 is an isometric side view of a wafer, partly broken away, depicting an arrangement of conductive coils associated with a series of elements of multielement magnetic heads, according to this invention.
- FIG. 3 is an isometric view of a magnetic write head assembly formed with the closure piece of FIG. 1E and the wafer, the closure piece and wafer being shown as separated for the purpose of clarity and explanation.
- the process of fabricating a closure piece for magnetic head assembly includes the step of forming a sandwich structure (FIG. 1A) of a ferrite layer 10, disposed between layers 12 and 14 of nonmagnetic barium titanate ceramic (BTC).
- BTC nonmagnetic barium titanate ceramic
- the ferrite is preferably diffusion bonded to the BTC layers. Diffusion may be accomplished in a fixture which is maintained at 900° Centigrade for one hour at 50 thousand lbs. per square inch pressure, by way of example.
- the layers may be glass bonded, in a well known manner.
- the sandwich structure is sliced centrally along the length of the ferrite layer, i.e., in the longitudinal direction, to produce two similar laminates 16 and 18, each having a relatively thin layer of ferrite 20 and 22 respectively, supported by the relatively thick BTC substrate 12 and 14 (FIG. 1B).
- the laminates 16 and 18 are ground, lapped and polished to a desired thickness.
- the ferrite layers 20 and 22 may each be about 0.20 mm. thick and the BTC layers 12 and 14 about 2.0 mm. thick.
- the surface of the exposed ferrite layer 20 of laminate 16 is saw cut toward the BTC layer 12 to a depth of about 0.25 millimeters, such that the resultant slots 24 are about 50 microns wide and 1.5 mm. long, by way of example.
- the BTC layer 12 serves as a support for the ferrite layer 20 and minimizes cracking and breakage during processing of the ferrite.
- the slots 24 are filled with a high temperature glass in a liquid state which solidifies when cooled (FIG. 1C). Grooves 26 and 28 are cut through the ferrite layer 20, exposing the BTC layer 12 at the grooved areas, thereby separating the slotted ferrite region from the remaining ferrite.
- the slotted grooved laminate is then bisected by a transverse cut 29 through the center of the slotted area and the BTC layer 12, as shown in FIG. 1D.
- two completed closure pieces 30, such as illustrated in FIG. 1E, are obtained.
- the laminate 18 is processed in the same manner as laminate 16 to provide two additional similar closure pieces.
- the closure piece 30 is joined, by epoxy for example, to a wafer 32 that will form the transducing gap 33 and complete the magnetic flux path.
- the wafer 32 includes electrical coils and leads for conducting current representative of signals to be recorded on or read out from a magnetic medium or tape 34 (FIG. 3).
- the wafer 32 is formed with a ferrite substrate 36 on which a spacing layer 38 of Al 2 O 3 is deposited by sputtering for example.
- a series of thin film conductive coils 40A-N which may be made of gold, copper or aluminum, are vapor deposited in a common plane on the spacing layer 38, and are positioned so that each discrete coil 40A-N is associated with a corresponding track element 42A-N, represented in FIG. 3.
- Electrical leads 44 are solder connected to the terminals of each coil to enable passing current to and from the coils for interaction with the magnetic circuit of the head assembly.
- the ferrite may be penetrated and slotted to a shallow depth.
- the shallow cuts allow the use of smaller and narrower cutting saws and wheels that are more accurate than those conventionally used to saw ferrite material used in magnetic head manufacture. In this way, parallelism and precise spacing of the tracks are more easily achieved. Less ferrite material is needed, and the reduction of ferrite breakage improves production yields. Furthermore, only a single glass is needed for this novel construction, as compared to the magnetic head structures that require a two glass bonding, i.e., a high termperature and a low temperature glass.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Magnetic Heads (AREA)
Abstract
Description
Claims (3)
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/253,959 US4396967A (en) | 1981-04-13 | 1981-04-13 | Multielement magnetic head assembly |
JP56198696A JPS57169917A (en) | 1981-04-13 | 1981-12-11 | Multielement magnetic head-assembly |
DE8282100972T DE3271964D1 (en) | 1981-04-13 | 1982-02-10 | Multielement magnetic head assembly and method of making such assembly |
EP82100972A EP0062739B1 (en) | 1981-04-13 | 1982-02-10 | Multielement magnetic head assembly and method of making such assembly |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/253,959 US4396967A (en) | 1981-04-13 | 1981-04-13 | Multielement magnetic head assembly |
Publications (1)
Publication Number | Publication Date |
---|---|
US4396967A true US4396967A (en) | 1983-08-02 |
Family
ID=22962358
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US06/253,959 Expired - Fee Related US4396967A (en) | 1981-04-13 | 1981-04-13 | Multielement magnetic head assembly |
Country Status (4)
Country | Link |
---|---|
US (1) | US4396967A (en) |
EP (1) | EP0062739B1 (en) |
JP (1) | JPS57169917A (en) |
DE (1) | DE3271964D1 (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4774755A (en) * | 1984-10-31 | 1988-10-04 | Sanyo Electric Co., Ltd. | Magnetic head and process for producing same |
US4843486A (en) * | 1986-04-03 | 1989-06-27 | Hitachi, Ltd. | Multi-element magnetic head and method of fabricating the same |
US4872079A (en) * | 1987-07-28 | 1989-10-03 | Applied Magnetics Corporation | Thin film magnetic head with a leveler layer |
US4884157A (en) * | 1987-07-28 | 1989-11-28 | Applied Magnetics Corporation | Thin film magnetic head with coil windings receiving trench |
US4899434A (en) * | 1987-07-28 | 1990-02-13 | Applied Magnetics Corporation | Method of making a thin film magnetic head with a leveler layer and superstrate |
US5055957A (en) * | 1989-06-19 | 1991-10-08 | International Business Machines Corporation | Method of making low wear glass for magnetic heads |
US5063468A (en) * | 1990-05-08 | 1991-11-05 | North American Philips Corporation | Compatible magnetic head assembly |
US5211734A (en) * | 1989-03-31 | 1993-05-18 | Tdk Corporation | Method for making a magnetic head having surface-reinforced glass |
US5778514A (en) * | 1993-01-06 | 1998-07-14 | Das Devices, Inc. | Method for forming a transducing head |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1119475A (en) * | 1993-03-16 | 1996-03-27 | 达斯设备公司 | Mig and thin film hybrid read/write head |
US7841069B2 (en) * | 2007-08-30 | 2010-11-30 | International Business Machines Corporation | Method for manufacturing a thin closure magnetic head |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3145452A (en) * | 1958-03-24 | 1964-08-25 | Iit Res Inst | Method of making a magnetic head |
US3157748A (en) * | 1961-03-24 | 1964-11-17 | Gen Electric | Magnetic transducer |
US3613228A (en) * | 1969-07-02 | 1971-10-19 | Ibm | Manufacture of multielement magnetic head assemblies |
US3859663A (en) * | 1973-06-18 | 1975-01-07 | Sperry Rand Corp | Multichannel transducer with glass support elements |
US3925884A (en) * | 1972-12-29 | 1975-12-16 | Derek Frank Case | Method of manufacturing multi-track magnetic heads |
US4366518A (en) * | 1980-09-02 | 1982-12-28 | International Business Machines Corporation | Multi-track head assembly |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3579214A (en) * | 1968-06-17 | 1971-05-18 | Ibm | Multichannel magnetic head with common leg |
US3626396A (en) * | 1968-10-03 | 1971-12-07 | Ibm | Thin-film magnetic recording head |
US3909932A (en) * | 1973-10-23 | 1975-10-07 | Ampex | Method of manufacturing a multitrack magnetic head |
US4072993A (en) * | 1974-11-12 | 1978-02-07 | Matsushita Electric Industrial Co., Ltd. | Multi-element magnetic head |
JPS5184618A (en) * | 1975-01-22 | 1976-07-24 | Nippon Electric Co | JIKI HETSUDO |
US4298899A (en) * | 1979-12-17 | 1981-11-03 | International Business Machines Corporation | Magnetic head assembly with ferrite core |
-
1981
- 1981-04-13 US US06/253,959 patent/US4396967A/en not_active Expired - Fee Related
- 1981-12-11 JP JP56198696A patent/JPS57169917A/en active Pending
-
1982
- 1982-02-10 DE DE8282100972T patent/DE3271964D1/en not_active Expired
- 1982-02-10 EP EP82100972A patent/EP0062739B1/en not_active Expired
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3145452A (en) * | 1958-03-24 | 1964-08-25 | Iit Res Inst | Method of making a magnetic head |
US3157748A (en) * | 1961-03-24 | 1964-11-17 | Gen Electric | Magnetic transducer |
US3613228A (en) * | 1969-07-02 | 1971-10-19 | Ibm | Manufacture of multielement magnetic head assemblies |
US3925884A (en) * | 1972-12-29 | 1975-12-16 | Derek Frank Case | Method of manufacturing multi-track magnetic heads |
US3859663A (en) * | 1973-06-18 | 1975-01-07 | Sperry Rand Corp | Multichannel transducer with glass support elements |
US4366518A (en) * | 1980-09-02 | 1982-12-28 | International Business Machines Corporation | Multi-track head assembly |
Non-Patent Citations (1)
Title |
---|
IBM/TDB vol. 7, No. 11, Apr. 1965, p. 993, "Fabrication of Narrow Track Width, High-Density Ferrite Heads", by Frost et al. * |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4774755A (en) * | 1984-10-31 | 1988-10-04 | Sanyo Electric Co., Ltd. | Magnetic head and process for producing same |
US4843486A (en) * | 1986-04-03 | 1989-06-27 | Hitachi, Ltd. | Multi-element magnetic head and method of fabricating the same |
US4872079A (en) * | 1987-07-28 | 1989-10-03 | Applied Magnetics Corporation | Thin film magnetic head with a leveler layer |
US4884157A (en) * | 1987-07-28 | 1989-11-28 | Applied Magnetics Corporation | Thin film magnetic head with coil windings receiving trench |
US4899434A (en) * | 1987-07-28 | 1990-02-13 | Applied Magnetics Corporation | Method of making a thin film magnetic head with a leveler layer and superstrate |
US5211734A (en) * | 1989-03-31 | 1993-05-18 | Tdk Corporation | Method for making a magnetic head having surface-reinforced glass |
US5055957A (en) * | 1989-06-19 | 1991-10-08 | International Business Machines Corporation | Method of making low wear glass for magnetic heads |
US5063468A (en) * | 1990-05-08 | 1991-11-05 | North American Philips Corporation | Compatible magnetic head assembly |
US5778514A (en) * | 1993-01-06 | 1998-07-14 | Das Devices, Inc. | Method for forming a transducing head |
Also Published As
Publication number | Publication date |
---|---|
DE3271964D1 (en) | 1986-08-21 |
JPS57169917A (en) | 1982-10-19 |
EP0062739A2 (en) | 1982-10-20 |
EP0062739A3 (en) | 1983-03-09 |
EP0062739B1 (en) | 1986-07-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5237476A (en) | Thin film tape head assembly | |
US3846841A (en) | Multiple magnetic head devices | |
US3613228A (en) | Manufacture of multielement magnetic head assemblies | |
US4435900A (en) | Method of manufacturing a magnetic head unit | |
US4396967A (en) | Multielement magnetic head assembly | |
JPS63225909A (en) | Thin film magnetic head | |
US5826326A (en) | Method for manufacturing a composite metal and ferrite head transducer | |
US3601871A (en) | Method for fabricating magnetic read-write head array and product | |
US3479738A (en) | Magnetic heads | |
US4774755A (en) | Magnetic head and process for producing same | |
US4217613A (en) | Magnetic transducer head core | |
US3909932A (en) | Method of manufacturing a multitrack magnetic head | |
US4860140A (en) | Magnetic head closure having ferrite substrate and closure and conductive thin film coil deposited in recess of substantially same shape in ferrite substrate | |
US3839784A (en) | Method for fabricating magnetic read-write head array and product | |
US4899241A (en) | Method of manufacturing a magnetic head having a thin film in a portion of its core | |
US5402294A (en) | Laminated, high frequency, magnetic transducer and manufacturing method therefor | |
EP0224342A2 (en) | A magnetic head for recording and playback | |
US4110902A (en) | Method for manufacturing a magnetic head for video signal | |
US5079664A (en) | Magnetic head with a laminated magnetic film thicker than a track width | |
US3843968A (en) | Magnetic head | |
US5276959A (en) | Method of manufacturing a magnetic tape head | |
US5691866A (en) | Magnetic head and method of manufacturing the same | |
JPS6233309A (en) | Manufacture of layered head piece with azimuth | |
US4843486A (en) | Multi-element magnetic head and method of fabricating the same | |
US6038109A (en) | Magnetic head and method of manufacturing the same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: INTERNATIONAL BUSINESS MACHINES CORPORATION, ARMON Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:ARGUMEDO ARMANDO J.;CHOW WILLIAM WAI-CHUNG;DUNN LOWELL E.;AND OTHERS;REEL/FRAME:003879/0917;SIGNING DATES FROM 19810402 TO 19810408 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, PL 96-517 (ORIGINAL EVENT CODE: M170); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 4 |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
LAPS | Lapse for failure to pay maintenance fees | ||
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 19910804 |